ASN decided to uprate as level 2 on the INES scale an event related to non-compliance with the requirements applicable to labelling, storage and on-site transfer of wet fissile materials

On September 26th 2012, the company FBFC (subsidiary of AREVA) notified ASN of an event related to non-compliance with the requirements applicable to packaging, storage and on-site transfer of wet fissile materials within its nuclear fuel fabrication facility in Romans-sur-Isère (Drôme).

AREVA – FBFC suggested ASN to rate this event at level 1 on INES.

The event occurred in the premises of the basic nuclear installation dedicated to the production of PWR fuel. Within the facility, transfer of fissile materials between workshops is sometimes carried out by using cylinders containing fissile materials that are either dry or wet.

So as to prevent criticality risks, labelling, storage and transfer requirements for cylinders containing wet fissile materials are more stringent than for those containing dry materials. In particular, the requirements specify that these cylinders containing wet fissile materials must be labelled and handled manually one by one.

On September 24th 2012, while opening a cylinder, an operator detected that a cylinder containing wet fissile materials was on the transfer carriage dedicated to cylinders containing dry fissile materials. This cylinder was not labelled properly and did not comply with the storage and transfer requirements for cylinders containing wet fissile materials.

As soon as this deviation was brought to light, all workshop-to-workshop transfers were stopped in order to check exhaustively all the carriages and cylinders within the facility. Other deviations from the requirements applicable to labelling, storage and on-site transfer of wet material cylinders were detected.

ASN performed an inspection of the facility on September 28th 2012. It highlighted that several cylinders were concerned by non-compliance with requirements applicable to labelling, storage and on-site transfer of wet materials. A lack of safety culture and of integration of the experience feedback has also been noted.

This event had no impact on the workers or the environment.

However, due to the lack of safety culture and of integration of experience feedback showed by AREVA FBFC, as well as of the number of cylinders concerned by the event, ASN uprated it as level 2 on the INES scale.

In addition, given the deviations of AREVA FBFC’s management of the criticality risk, AREVA FBFC has been requested by an ASN resolution to deeply analyze these events and to implement sustainable measures. In the meantime, AREVA FBFC is requested to set transitional provisions to prevent criticality risk associated with the management of cylinders containing waste from the grinding machine.